Well for example the left island:
To start with, you can deduce that the two tiles on the left and right must contain mines:
because there can only be two mines around the centre tile, so the left and right 2s must each contribute one apiece to that, otherwise you end up with a contradiction. Knowing that, you can reveal the two above the centre, as we know neither mine can be up there.
Which reveals two 4s, so we can fill in the unknown tiles around these as containing mines, and finally we now know the two bottom unrevealed tiles must be empty.